Process of and apparatus for electrorefining copper or other metals



(No Model) 0. R. FLETCHER. PROGBSS or AND APPARATUS FOR ELEGTROREPINING0012mm OR OTHER METALS. No. 586,171. Patented July 18, 1897.

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NITED STATES PATENT rrrcn.

CHARLES R. FLETCHER, OF BOSTON, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent No. 586,171, dated July 13,1897. Application filed January 27, 1892. Serial No. 419,417. (Nomodel.)

T 0 all whom it iii/by concern Be it known that I, CHARLES R. FLETCHER,a citizen of the United States, residing at Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Apparatus for the Electrorefining of Copper or othermetals, and in the Process of Electrodeposition, of which the followingis a specification, reference being had to the accompanying drawings,forming a part of the same.

My invention relates to an electrolytic process and apparatus for theelectro refining and deposition of metals-such, for example, ascopper-in the form of slabs, bars, strips, sheets, and irregular formsfrom impure metalssuch, for example, as crudeingot copper, blister orblack copper. The process and apparatus may, however, be employed forthe deposition of other metals; also, in the electroplating of metalsupon hollow or tubular forms of cathodes, as will be explained.

The invention relates, especially, to a method of combined andcontinuous application of heat and electricity to the cathode, as willbe explained, and to the construction of the electrolytic cathode tocarry out this process.

At many times attempts have been made to produce copper and other metalsby electrodeposition in the general process called electrolysis, so thatthe resulting copper, commonly called electrolytic copper, or othermetals shall bein a state of compact, homogeneous, malleable, andductile metal. Atprescut the electrolytic copper or other metal isproduced in a crystalline brittle form quite unlike the metal producedby melting and subsequent cooling in proper molds. To produce copper andother metals in the reguline condition, the process has been either veryslow or complicated, and then the deposited metal has lacked importantdesired qualities.

My invention simplifies the conditions of the electro process andfurnishes means whereby the electrodeposition of metals can be carriedon with great rapidity consistent with the production of smoothmalleable and ductile copper and other metal, and whereby metal may beproduced of standard chemical purity, highest electrical conductivity,normal tensile strength, and of higher specific gravity than hitherto.

, My invention consists, first, in an electrolytic process combined witha method of heating the hollow cathode or preferably the cylindricalrotating cathode, whereby during the electrodeposition upon thecathode-surface there is maintained a continuous evolution of heatwithin the metallic cathode, which is conducted from withinoutward,hence upon and through the electrodeposited metal. is therebythat under appropriate conditions relating to the maintenance of theelectro deposition, which varies according to the metal deposited, I amenabled to produce the results which I have specified as being so long adesideratum.

The apparatus which embodies the second part of my invention comprises atank or vat for containing an electrolytic or conducting solution, oneor more cathodes for receiving a deposited metal, and one or more anodeswhich are dissolved by the action of an electric current and transferredto and deposited on the cathode or cathodes, the general object being toobtain pure from impure metal, and the special object being to obtainthe deposited metal in a condition when the several physical propertiesbefore mentioned present themselves. In the manner of heating of thecathode and construction most convenient to carry out thiscontinuousheatin g process lies the subject of this part of myinvention. When liquids pass from the liquid to the gaseous state, alarge amount of heat, as is well known, is absorbed. When, on thecontrary, the vapor passes back into the state of liquid, it gives out adefinite amount of heat. This latent heat I find most convenient for theheating of the cathode, and in carrying out my process I preferably usethe vapor of water, (steam) Another plan is to arrange resistance-coilsinside the cathode form or cylinder, and by means of electricity heat isproduced in these coils. I am enabled thus to produce equallysatisfactory results on the cathode. I heat,

it steam is used, the cathode form or cylinder to a temperaturedepending upon the metal deposited and thenature of the solution.

In the case of copper I raise the temperature usually from 180 to 212Fahrenheit. By this means all gases which may collect upon the cathodeare driven off, and thus polarization is also diminished. NVhendesirable to heat the steam or vapor to a temperature above theboiling-point of water, I do so by means of the electroheatedresistance-coils within the cathode, and this superheating of vapors bythis means I also claim as part of myinvention. It will be seen that Ialso indirectly heat the solution by these means which, of course, I donot claim as new, except in the manner of heating the electrolyte.

In the drawings hereto annexed, Figure 1 is a vertical central sectionof an apparatus constructed and adapted for carrying out my invention,and Fig. 2 is a perspective view of a modified form of cathode.

In carrying out my invention I prefer to use a cylindrical cathode A,mounted in a tank A and capable of rotation therein, as by this meansattention can be more conveniently given to the deposited metal whichcontinuously appears in view, also more powerful currents of electricitymay be brought to bear upon small surfaces of metal and the rate ofdeposit hastened, and all conditions embraced in my invention moreaccurately carried out.

The cathode is or may be prepared in the usual manner, but I prefer touse an iron pipe covered with electrotype metal, which is turned down onthe surface so as to prepare it for receiving a deposit of metalsmoothly if sheets are to be made, or otherwise, according to thedesired form of the deposit. The heads or ends B of the pipe or cylinderare then inserted and the joints then soldered.

The shaft or axis C of the cylinder I make of a metallic pipe or tubeprovided with a pulley D and connected with a steam-pipe E, from whichthe steam is introduced into the hollow cathode through pin-holes F,bored through that portion of the hollow axis which is within thecathode. I also mount on this shaft within the hollow cathoderesistancecoils G, connected by insulated wires that pass through thehollow shaft with collectingrings H, mounted on the end of said shaft.These rings in turn are connected with a suitable source of current, andwhen suificient electricity is passed through the coil they are heated.

In some cases the cylindrical cathode may be made without heads, asshown in Fig. 2. In such cases I employ a wooden or other insulatingcylinder or tube K, around the surface of which are arranged fiatheatingcoils G. Over the surface thus wired I secure in any propermanner a sheet of electrotype metal L as a cathode to receive thedeposit. There are several convenient methods of thus heating theinterior of metallic cathodes and from within outward, when the desiredcontinuous radiation of heat through and out lation due to melting andcasting.

from the metallic cathode is sustained during the deposition of metalupon the same.

The electric currents and circuits to sustain the deposition upon thecathode may be applied as usual, and the general electrolytic process itis otherwise unnecessary to describe, as it is well understood andvaries with the metal under treatment.

I have shown in the drawings an ordinary form of anode M in a vat ortank in proximity to the rotating cylindrical cathode. One terminal ofthe source of electricity is connected with the anode through aninsulated conductor N and the other to the cathode through a brush P,that bears upon its surface.

There are several important advantages in the process and apparatusherein described, which are embraced chiefly in the resultant metaldeposited under the conditions above set forth, the properties of whichare those more or less of pure metal which has been melted and thencast, while it is free from the impurities arising from coal or manipu-Thus by my invention I obtain electrodeposited metal in sheets suitablefor immediate use or strips, bars, and forms ready either for use or forall mechanical purposes. I obtain pure deposited metal directly, whichheretofore has only been accomplished by various mechanical and othersteps in addition to the electrodeposition.

hat I claim is 1. The improvement in the art of depositing metals byelectrolysis which consists in dissolving by an electric current ananode immersed in an electrolytic bath and depositing the metal upon acathode supported in the bath, and maintaining in the interior of thecathode during such deposition a source of artificial heat, whereby theheat is conducted outward through the metal as it is deposited.

2. An apparatus for refining and depositing metals by electricitycomprising in combination a tank or vat, one or more anodes and a hollowrevolving cathode mounted on a hollow shaft connected with a source ofsteam, as set forth.

3. The method, herein described, of heating the cathode of anelectrodeposition-tank, by introducing steam into the hollow interior ofthe same, and superheating the steam by passing a current of electricitythrough resistance-coils contained within said cathode.

4:. The combination with a hollow rotating cathode of a source of steamconnected with the interior thereof, electric heating-coils con tainedwithin the cathode and electrical connections therefrom to a source ofelectric current, as set forth.

CHARLES R. FLE TONER.

Witnesses:

L. C. SARGENT, J OSEPH L. KEITH.

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